1. Field of the Invention
The present invention relates to an actuator for a mobile optical recording/reproducing apparatus, and, more particularly, to an actuator for a super-slim mobile optical recording/reproducing apparatus having an asymmetric electromagnetic drive structure.
2. Description of the Related Art
Recently, as the use of mobile optical recording/producing apparatuses employing optical recording media is rapidly increasing, research on high-density optical recording media is being actively conducted.
For a user's convenience, a mobile optical recording/reproducing apparatus must be small-sized and able to reproduce/record high density information. In order to meet these requirements, an actuator for a focus drive and a track drive of an objective lens employed in the optical recording/reproducing apparatus must be miniaturized.
Referring to FIG. 1, a micro-actuator of a conventional mobile optical recording/reproducing apparatus includes a stationary member 13 provided on an end portion of a driving arm 11, a movable member 15 movable in a track direction (X-axis) and a focus direction (Y-axis), a magnetic driving unit 20 to magnetically drive the movable member 15, and a suspensor 17 to support the movable member 15 as the movable member 15 moves with respect to the stationary member 13, and to be used as a conducting path. The movable member 15 is provided with an objective lens 16 to focus incident light.
The magnetic driving unit 20 includes yokes 21 and magnets 23, which include a magnetic circuit, a focus coil (not shown) installed at both ends of the movable member 15, and four track coils 25. The focus coils and track coils 25 are provided at a side wall of the movable member 15. The suspensor 17 includes four wires, and supports the movable member 15 symmetrically with respect to the stationary member 13.
The actuator of the conventional mobile optical recording/reproducing apparatus as described above is a common symmetrical structure adopting four wires, in which components including a plurality of coils are arranged in a narrow space to provide a small-sized configuration. Since each component is arranged in a longitudinal direction of the wire at the side wall of the movable member 15, the space occupied by each component is small. Accordingly, there is a problem in that the characteristic of the actuator is deteriorated. In this case, the actuator has a height of about 4 to 5 mm, and it is difficult to obtain an actuator with a height less than the above values.
The conventional actuator includes the track coils 25 and the focus coils as the magnetic driving unit, so that the actuator can be controlled in the focus direction and the track direction only. Since the actuator does not have tilting driving means, there is a limitation regarding recording/reproducing high density data.